Help - New Nest, no fan coming on!

[Secarg3]

I just got the Nest installed yesterday—basic thermostat.  Seemed to be fine yesterday, heating and cooling tested.  

Since last night, when I changed some of the presets and set up a schedule, now the FAN doesn’t come on.  I can hear the compressor firing up, the system says heating, but it’s not coming out of the vents because no fan is running to blow it around.  I see in the settings it shows the fan is set to auto. 

can anyone offer some guidance?

THANK YOU…

[Houptee]

How did you wire it up?

Do you have the G wire connected? That is for the fan.

Do you have a C wire connected?

Post pics of before and after of the wiring and is this a Heat pump or a gas furnace with ac system?

[Secarg3]

Hi.  I only have after, as it was installed already.  It’s a heating/AC system, gas furnace located in the crawl space upstairs.  

Both of those wires look connected.  It won’t allow me to unload a photo.

When it was set up, it worked fine for the first day.  Then the fan stopped coming on.  I reset the Nest, and re-set it back up.  Heater comes on.  AC comes on with the fan.  Just did a second re-set to factory settings and I think it just finally clicked on…?

[CoolingWizard]

On some gas furnace, the fan does not start until the heat exchanger gets hot.  How long do you wait for the blower fan to come on?  If your manually turns the fan, does it indeed start blowing?

The AC Cooling Wizard

[Secarg3]

Quite a bit of time.  It was working earlier, with fan, but tonight the room is currently at 72, and i goosed it up to 75.  But while I can hear the furnace power up, no fan comes on.  Is this because it’s not “needed?” and can’t?

I can manually turn on fan.  Earlier today, when the room was 68 and I asked it to come on to heat to 74, the furnace kicked on and the fan came on pretty quickly.

Thanks so much for trying to help—I appreciate it so much!

[CoolingWizard]

Hmmm, this is ver puzzling then.  How long do you wait for the blower fan to come on? If the furnace is on, and it gets to hot with no blower running , the furnace will shut off on an over temperature safety. Does that happen? 

The AC Cooling Wizard

[EdwardT]

Hi folks,

@CoolingWizard and Houptee, thanks for the help!

@Secarg3, how's it going with your Nest Thermostat? Still need our help?

Thanks,

Edward

[Secarg3]

thank you…. i thought it was resolved. Fan came in with heater Saturday and everything was fine. Sunday and Monday, no fan. I cannot force the fan on. It says it’s heating but sometimes I cannot even hear the furnace fire up. So I don’t know…

I honestly think if this is a smart thermostat, I need to go back to the dumb ones. 
Btw, when I flip it to AC, compressor and fan pop right on…

[Jenelyn_O]

Hi there,

Chiming in — I just want to follow up if you're still encountering the issue. Please let me know as I'll be willing to assist you from here. 

Best,

Jenelyn

[Jenelyn_O]

Hi Secarg3,

I wanted to follow up and see if you still need help. Please let me know if you are still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.

Best,

Jenelyn

[EmersonB]

Hi everyone,

@Secarg3 just one quick final check in here since activity has slowed down. We'll be locking the thread in the next 24 hours, but if you still need help, we would be happy to keep it open. If there's more we can do, just let us know.
 
I appreciate the help, Jenelyn, CoolingWizard, Houptee and Edward.
 
Regards,
Emerson